docs: def rel_humid_from_db_dpt(db_temp, dew_pt):
      """Relative Humidity (%) at db_temp (C), and dew_pt (C).
      """
      pws_ta = saturated_vapor_pressure(db_temp + 273.15)
      pws_td = saturated_vapor_pressure(dew_pt + 273.15)
      rh = 100 * (pws_td / pws_ta)
      return rh